Background: Olopatadine 0.2% is the first topical ophthalmic antihistamine/mast cell stabilizer indicated for once-daily dosing. Objective: This review provides a comprehensive description of the pharmacology of the olopatadine molecule, as well as of the clinical efficacy, tolerability, and safety of olopatadine 0.2% ophthalmic solution. Methods: References cited in this review were obtained from the PubMed biomedical literature database. Also included were several posters presented at nationally renowned ophthalmology-related conferences. Results/conclusion: Olopatadine 0.2% was found to be a safe and effective medication for the reduction of itching with a duration of action of up to 24 h. The added convenience of a once-a-day dosing regimen is a major advancement in this drug class.